Submarine boat



Jan. 16, 1940. G. cAPRoNl SUBMARINE BOAT Filed April 6, 1938 :ssheets-sheer 1 jarzni @profili Jan. 16, 1940.

G. CAPRONI SUBMARINE BOAT Filed April 6. 1938 A l 2n Fig 2 3Sheets-Sheet 2 G. CAPRONI SUBMARINE BOAT `lan. 16, 1940.

Filed April 6, 1938 3 Sheets-Sheet 3 Patented Jan. ,16, y1940 UNITE ivfman SUBMARINE BOA'l` l Gianni Caproni, Milan, Italy e l Y ApplicationApril 6, 1938, Serial No. `200,446

g In Italy April 12, 1937 29 Claims. (Cl. 114-16) The present inventionrelates to submarine boat operation and has for its object to aiiord animproved method and plant for the propulsion of submarines by means ofinternal combustion 5 engines.

The principle is already known of substituting for the air the internalcombustion engines need.. the burnt gases which the engine expels, afterhaving them regenerated by the addition l of fresh oxygen; and also thegreat desirability 'is known, of employing said principle in subaqueousnavigation, replacing there the electric oxygen, (6) `changing over fromthe supply of.

surrounding air to that with oxygenated exhaust gas, and vice versa,according to whether under- Water travelling or surface travelling is.to be performed, ('7) providing suitable cooling water reserves so asto compensate for evaporation, (8) providing controlled apertures forthe introduction of the surrounding air, for the discharge of the gasesinto the atmosphere during the surface travel, and for the discharge, atthe moment wanted, of the fluid 'under pressure, stored in the tankwhich receives the condensing water.

The plant for carrying out these operations' comprises at least oneinternal combustion `en gine, an oxygen reserve, means for the formation40. of the combustible mixture, interdependently controlled, commutatingmeans respectively for the supply of surrounding air or of oxygenatedexhaust gas, means for the cooling of the exhaust gases, means forconditioning these gases in the 45 most suitable manner for propermixing and foi' their -silent discharge, means for cooling theV enginein closed cycle, combined with means for compensating the losses ofcooling water on account of evaporation,-and controlling means for 50the communication with the exterior of the craft of the air intake andthe exhaust port of the engine and of the pressure tank, and meansmeerence to the annexed drawings, given only by way of example, andwhich show an embodiment of the plant utilizing an explosion engine. y

Figure A1 shows a cross section of the submarine showingdiagrammatically the whole 5 plant;

Fig. 2 shows particularly an axial section of the double valvechanging-over device;

Fig. 3 shows in particular the mixing device;

Fig. 4 showsthe details of the safety valves; w

Fig. 5 shows a modication of the pressure tank, relating to another.manner of removing the excess of gas..

Fig. 6 shows a device for the optimum utilization of the oxygen supply.u

With reference to Fig. 1`, I indicates the main skin or shell of thesubmarine, 2 being the nor. mal water line of the emerged boat.

The engine is cooled by circulation of soft water actuated by thecentrifugal pump 4. The water circuit consists of the tube 6, motor 3,-tube, serpentine or cooling coil 1, which is con# tinuously surroundedby cold water, and of tube 8. On the upper tube 6,*.the upp'er tank 9 isarranged in a way to maintain the charge, while the evaporationdischarges through the tube I Il into the tank II; later explained soAas to wet not excessively the atmosphere of the submarine. The supplyof water to oiiset the evaporation is obtained by opening now and thenthe cock I2 inserted in the tube I3, which extends to the bottom of alower tank I4 where, as will be eX- plained, distilled water underpressure will be always stored.

The carburetor I5 is preferably of the so'-` 35 called inverted verticaltype to the end that any dribbling of petrol when running empty orduring stopping will deposit in the engine itself instead of droppinginto a place where it would cause danger of explosion. The carburetorcould 40 be fed with fuel by gravity or by means of a pump. i

In the embodiment shown, the feeding takes place by descent from thetank I6 through the tube 1 provided with the cock la; the car 45bureteras well as the said tank are hermetically tight, either to hinderthe escape of fuel vapours and the dropping into the hold of thesubmarine, l

vor to permit .of varying automatically the feed pressure of the fuel inaccordance with the variation of that of the burning medium: for thispurpose, the tank is` closed by the plug or cap I9, l

chanically connecting the various members to attain the desired results.I6 Now. the invention will be explained with refand the tube 20 bringsit in constant communication with the feed conduit-*2l of the burning Vmedium. whether air or gas, -while the-carf' buretor, because of itsconstruction, is internally in constant communication with the top ofthe constant level basin.

In the case of -fuel supply by means of a pump, the tank may be arrangedat the bottom, and the connection between pump, .tank and carburetor maybe afforded by systems as commonly in use for aircraftmotors providedwith compressor. A double valve commutating device 22-23, the normal rodof which slides, within a special guide, at the axis of the feed conduit2i, puts the carburetor in communication with the atmosphere through thepipe 24 or through the pipe 25 with the oiwgenated gas, and thisaccording to whether said rod stands in one or in the other of theterminal positions, that in Fig. l

being considered the position for running with l The double valve iscontrolled by hand through a lever 26 and combined with means whichshall be explained hereafter, owing to which, under exclusion of anyintermediate position, it will be possible to shift said lever only intoone or the other of the extreme positions.

' The discharge of the engine takes place through a pipe 271 and a,serpentine coil 28; this coil being always completely surrounded by theexternal cold water so that the water vapour it Acontains will becomewholly condensed by such intense cooling. At the outlet of theserpentine28 a gas will be delivered which consists prevailingly of carbonio`anhydride and condensation water containing a little carbonio anhydridein solution. 1

This mixture enters into the lower part of the tank il through theperforated pipe 29; the water deposits in the conic bottom of the tankyl i, while the gas tends to rise subject to a series of throttlings andexpansions in the labyrinth of diaphragms 36, which practicallyextinguish the pressure fluctuations of said gas in the manner ofautomobile silencers.

From the top of the tank il! the cold gas can discharge into theatmosphere through the pipe 3i when the double valve 22-23 is inposition to run 'with air (in which instance the flap valve 32 is openas well as the safety valve 5t which will be further explained), or thegas may ow towards the engine through the p ipe 25. when the doublevalve 22--23 stands in the position to run with gas (in which case thevalve 32 is closed and the\,safety valve 56 is open or closed inaccordance with whether the submarine is aoat or immersed). l

The ap. valve 32 is connected, by meansof the link or drawbar 33, withthe same lever E@ which controls the double valve 22-23;

The gas coming out from the tank li and passing on to feed the engine,at its entrance into the pipe 25 mixes with the oxygenoriginating fromthe high pressure flask battery 35i and passing'through a pressurereducer 35 regulated by lever 40 which controls the' throttle of thecarburetor, so that the quantity of oxygen will vary in proportion tothe quantity of gas consumed bythe engine in order to obtain a burningmevquent condensation of the fuel.

(cording to the speed of the submarine.

fore, in the suction piping 43 of the pump, a cock aimera dium which hasthe same content of oxygen at all ranges of the engine.

The mixing of the oxygen with the gas should be as homogeneous aspossible; for this, a mixing device 4l, hereinafter further described,is arranged in the pipe 25 at the entrance point of the oxygen; betweenthe mixer 4| and the double valve 22--23, a metal mesh 42 is disposed toextinguish the back flow of flames coming from the Carburettor.

The oxygen which is heavily cooled by its own expansion in the reducer35, would cause the congelation of the reducer itself with theconsequent stopping of 'the internal valves, and cause also an excessivecooling ofthe gas with the conse- For avoiding this, the pressurereducer 35 is warmed by means of a diversion of the hot exhaust gas,formed by the dynamic connection 43tubes 44. 45 and static connection46, which diversion is made upon the conduit 21.

Of course, also a warming device vof another type could be provided, forinstance an electric one. l

As the volume of water vapour drawn from the exhaust gas by way ofcondensation in the serpentine 28 is inferior to the volume of oxygenintroduced, the oxygenated gas available for the engine would be inexcess, and therefore a certain quantity must be removed preferablyalong with the condensation water. For this is provided a`suction'pressure pump 41 driven by the engine through the shaft 48.This pump yis arranged below the lowest point of the tank li in order tosuck out of the pipe 49, not only all the water which tends to deposit,but also the excess of gas, and to send this/.mixture of the tank i4already mentioned.

This tank is provided with an automatic exhaust valve 50, normally heldclosed by a light spring i and by the external water pressure.

The said valve opens when the pressure in the tank l exceeds slightlythe corresponding pressure at the shut-olif of the outside water, thusmaking the mixture escape. As the gas consists prevailingly of carbonioanhydride it will be rather completely dissolved exteriorly while itascends within the mass of external water.

'I'he quantity of gas which in addition to the condensation water isremoved by the cycle,

should depend on or vary according to the speed of the engine so as tomaintain the absolute 'feeding pressure of the burning medium constant,because properly on the basis of this constant pressure, thewhole oxygensupply equipment has been arranged and adjusted. For such purpose itwill not be suiilcent that the pump and the'engine rotate synchronouslyas the eciency of these machines follows rules which are a littlediierent and also for other reasons among which is the variableintensity of cooling of the gas, ac-

There- 52 is arranged which by means of a draw bar or link 53 isconnected with a manometric capsule 54 of the bellows type, whichthrough a pipe 55 communicates with the top of the tank ii beyond themailling action. When the pressure in said tank Il tends to fall, thecock 52, correspondingly, tends to throttle the suctin of the pump ,andvice versa.

The air feed tube 24 and as well the discharge tube 3i to theatmosphere', open towards 'outside of the boat, and this through .thesafety valves respectively 56' and 56. These latter are opened when theengine runs with air and the boat is emerged, while they willautomatically shut When the boat begins the submerging manoeuvre (thatis, after having changed-over to running with gas). This takes place inconsequence of the external water pressure in two manometric bellowscapsules 51 which are arranged slightly above or superior to the normalwater line of the emerged boat, and communicate with the outside eachthrough-a hole 58.

On account of their own elasticity said capsules tend to maintain openedthe valves, acting through links 59 and suitable levers action; but thewater pressure tends to shut them when it has acquired the superiority,which will happen when the submerging manoeuvre is initiated.

The purpose of these safety valves (which could be also controlled byhand) is the following: As concerns the valve 56', it prevents duringsubmersion the pipe 24 becoming filled with Water, which would preventthe changing-over to running upon air with the subsequent emergence; asconcerns the valve 56, instead, it prevents the outside water tricklingthrough the valve 32 and entering the tank Il, which would greatlyinterfere with running with gas.

The operation is as follows: With stopping motor, the lever 40 will bealways in the position of the closed carburetor so that the cock 36 forthe oxygen, connected to it, will also be shut; the lever 26 will be inthe position for running with air and, as a consequence, also the othercock 31 for the oxygen will be closed.

The starting and the running with air, therefore, take place only insurface running; the safety valves 56 and 56 are opened as also thevalves 22 and 32, while the valve 23 is closed. In this conditionthe-suction as well as the discharge take place liberally from and intothe atmosphere. The gas discharge, instead, is through the serpentine 28and the tank Il, so that, when the water vapour is condensed and thewater, by means of the pumpv 41 is removed, the gas escapes in coldstate and without pulsation, and thus without any noise.

The variations of the ranges are normal; operating the lever 40 of thecarburetor, the cock 36 will take part idly with the motion of the lever40 as the escape of the oxygen is prevented by the cock 31.

In order to change-over from running with air to that with gas, nothingis needed but, to bring the lever 26 rapidly into the opposed position,and this is so, whatever may be the range at which the engine is runningwith air. In fact, as the pressure of the oxygen has once for all beenadjusted in the reducer 35, the cock 36 regulates its discharge inaccordance with the range, on account of its -being connected with theap of the carburetor; the shifting of the lever 26 has shut the airsuction valve 22, opened the `gas inlet valve 23, closed the free escapevalve 32, and opened the cock 31 of the oxygen.

The pump 41 continues as before to perform its work, and the capsule 54regulates the suction of same, operating upon the cock 52 so as tomaintain the feeding pressure in the tank Il constant.

The starting with gas is also normal: it is suf- 'fcient to take care ofthis by regulating exactly is turning driven by its own little startingmotor,

by blocking the lever 40, in the case of vain attempt, before the enginestops. 'I'his is necessary to avoid an accumulation of oxygen in thepipe 25 and the tank Il, which would make impossible the star-ting byexcessively meagre mixture.

It is important that all the conduits which the exhaust gas transversesbefore and after the oxygenation, the mobile members they contain, andthe tank I4, must be of a non-oxidizable material. The rapidaccumulation of rust would form crusts which would be swept away intothe engine or the pump, thus damaging the one or the other. Y

With reference to Fig. 2, which shows an embodiment of the double valve,also here the two interdependently controlled valves are indicated by 22and 23; they are connected bythe rod 60 which slides in the guide 6|,and they put the carburetor I5 in communication with the air feedconduit 24 or with conduit 25 for charging by oxygenated gas. Theexternal control hand lever 26 is keyed on the pivot 62, together withthe internal fork 63, the hub of which constitutes a cam or tappetshaped as a pointed heart. Against this tappet, a wedge 65 of a pointedkey shape is pressed by means of a spring 64. In this way, the doublevalve is obliged to displace into one or the other of the two extremepositions and to remain therein, without stopping in an intermediateposition.

The valve 23 is concave towards the carburetor so as to give rise to theformation of whirls which ,r favour a further mixing of the oxygenatedgas coming from the pipe 25, and at the same time to prevent theantiflame meshl 42 being damaged* in Fig. 3: two little (propeller)screws 66 and 69 are keyed on a common shaft 10 and placed respectivelyin front and behind the longitudinal radial ribs 1|, which sustain theball bearing 12; the first screw 68 is movable with respect to thesecond one and has, thus, all the characteristics for maximum efliciencyor output (to give the maximum power while offering the minimumresistance to the passage of the gas); the second screw 69, driven bythe first one, must, instead, create again the gas whirlings which breakthe continuity of the gas flow between the fixed ribs 1| and the annularribs 13 also fixed, and so that said screw shall consume the minimum ofpower, it has very narrow blades. The oxygen which enters the annularchamber 14, coming from the cock 31, escapes through the little hoes 15aslantly bored into the ribs 1I. and is energically mixedpwith the gasby the whirling motion created, as has been seen, by the screw 69. Agrease cup 16 serves' to lubricate the ball bearings. v

In Fig. l, the two safety valves 56--56' are shown, for better clearnessin the drawings which are schematical, with the manometrlc capsules xeddirectly at the skin of the'submarine and connected with the valves, asby means of long slanting draw bars 59.

Fig. 4 shows a more practical and complete embodiment of the same idea.Each of the valves 56' and 56'has the stem jointed by pivot 11 to avertical draw bar 18. The manometrlc bellows capsule 51 is mounted onthe pipe 24 (or 3|) and operates through the double `joint 'i9 upon thedraw bar 18 by the intermediate lever 66 which at 8l is pivoted to thesaid bar, and at 82 to the fixed `support 83. The elasticity of thecapsule ktends to maintain the valve completely open until the joint'l'l .comes to stop against the guide of the rod, While a spring 84counterpcises the weight of the mobile equipment and of the watercontained in the capsule. of the capsule communicates with the wateroutside of the submarine through a small pipe 85 which opens near thenormal water line 2, while the bottom of the capsule is located a littleabove said line (see distance X above water level). With the beginningof the submersion manoeuvre, when the water lever 2' reaches a certainheight Y above the bottom of the capsule, the pressure ofthe waterovercomes the elasticity of the capsule and the various frictions, andthe capsule becomes longer thus closing the valve (for instance, with alevel distance Y=Zm and an effective surface of the capsule of 50 cm2the pressure said surface provides is 5 kg.).

The mobile equipment may have also a control by hand, independent orconnected with the mechanism which regulates the submersion, or with thelever 26 which alters the manner of feeding the engine.

In the foregoing description it has been stated that the oxygen reachesthe mixer under constant pressure controlled by the reducer 35, and thatthe feed of oxygen is maintained in the right and constant proportion tothat of the gas, by means of a cock 36 connected with the lever 40 ofthe throttle of the carburetor.

The same effect could be obtained by connection of the lever 40 withthat 86 of the reducer and omitting or by-passing the cock 36, saidconnection being made so ythat a greater opening of the Carburettorthrottle corresponds to a higher pressure of the oxygen at the outlet ofthe reducer. In Fig. 1 the said connection is schematically indicated bythe dotted line M. It is useful that in this case the reducer bebroughtl into the close neighbourhood of the cock 31, for

instance, at the place of the suppressed cock 36. According to thepreceding description, the elimination or exhaustion from tank I4 tooutside of the boat is continuous beginning with the moment at which inthe tank I4 a pressure is reached which is a little higher than that ofthe water outside.

Although the quantity of gas to be removed is small and the gas (whichis composed pre- 'vailingly of carbonio anhydride) is dissolved in themass of water which it is forced to pass in order to ascend to thesurface, it would be also of value, be it even'for a short time, to stopits discharge with a view to making the submarine path invisible throughthe elimination of bubbles. f- For this purpose, according to themodification of Fig. 5, the valve has a spring Ela much stronger thanthat in the preceding instance, adjusted so that the valve will openautomatically onlyV when the pressure in the tank I4 reaches the limitof safety of the resistance of the tank g itself; a hand lever 81,however, can open the VIV The inner chamber a, :renova opens the littlevalve 89 when the level of the water in the tank reaches a predetermineddepth, at which it maintains itself constant.

'Ihe pressure of the oxygen at the outlet of the reducer is of principalimportance for the regular working with gas; once regulated and set inright relation to the apertures of the throttle of the Carburettor andthe cock 36, it need no more be changed.

Now, it is known that with the most perfect pressure reducer, thepressure below or beyond the reducer begins to diminish when thepressure above in the flasks has gone down to about twenty atmospheres;from this moment, in order to prevent the mixturel of the burning mediumgetting gradually sooty by oxygen, thuscausing a gradually less perfectworking of the engine, it would be necessary to regulate the reducercontinuously by hand. But, yet, whenv the pressure in the flasks hasgone down to about ten would have become altogether impossible. And atthis point there would be a rather substantial quantity of oxygen in theflasks that the engine could not make use of.

The embodiment according to Fig. 6 remedies this inconvenience.

The diierent flasks 341, 342, 343, 344, are connected by a piping 34h; aset of three cocks 9|-92-93 is arranged to seclude the first bottle(which always is to feed directly the reducer 35) from all the others,and to set these for their part in ,communication with the first onethrough a compressor 94 driven by a motor.

,Normally the cocks 9| and 92 are closed, while v93 is open and thecompressor stands idle; in

that case all the bottles feed the reducer 35.

lWhen the pressure in the bottles is gone down to the critical one of,for instance, 20 atmospheres, the compressor is (again) ,set to work,

93 is shut while 9| and 92 are opened; the compressor makes all theoxygen contained in the other ones pass into the rst bottle 341 up tothe complete emptying of the others even down to less than one absoluteatmosphere. Now, the

compressor can be stopped and valve 9| closed.

In this way, the stock of oxygen will be better utilized, although thecompressor absorbs a certain power from vthe motor.

Of course, it will be convenient to carry out this operation, wheneverpossible, during the travel afloat, that is with the engine running withair.

In the case in which the plant comprises a combustion engine of theDiesel or similar type, the said installation in its whole may be thesame as in the above instance, save for the following modifications:

The carburetor is' omitted or replaced by a simple pipe which connectsthe upper passage or cross piece with the conduit of the engine; thefeed of air or of gasl does not require any regulation.

The accompanying fuel injection pump is of a common type preferably witha delivery variable according to the speed ranges; the lever 40, insteadof controlling the throttle of the carburetor, governs the device forthe variation of the injection, existing in thepump, said leverremaining connected with the cock 36 for the oxygen so Vv20 atmospheres,the proper working ofthe reducer` As the fue1 is not volatile, the tankls may communicate with the atmosphere of the sub- As a consequence, thepipe`20 may be claims.

Having now`described my invention and practical ways in which it may becarried out, what I claim as my invention is:

1. In a submarine boat containing an internal combustion engine withsupply and feed of liquid fuel thereto, a compressed oxygen supply witha regulable pressure reducer, and an engine cooling system with forcedwater circulation; the combination of a valved commutator deliveringselectively either exterior air or gas-oxygen mixture to the engine andhaving rst and second adjusted positions with a shifter or lever forreversing it, an air passage leading from a closable exterior inlet tothe commutator to supply air thence to the engine in the rst commutatorposition when running emerged, a gas-oxygen mixer having apassageleading therefrom to the commutator to supply such mixture thenceto the engine in the second position when running submerged, an engineexhaust gas passage having a cooling section and a muiiling section andleading thence to the mixer, with a branch passage leading to a closableexterior outlet to disch'arge gas `when running emerged, and an oxygenpassage leading from said pressure reducer to the mixer with a shut-oivalve.

2. The combination as in claim 1 and wherein the engine comprises asealed carburetor to which lead the fuel feedand the delivery of thecommutator. v

3. The combination as in claim 1 and wherein is a single controlleror`lever operable for shifting the commutator from first to secondposition for submergence and coordinately opening the oxygen shut-olivalve, and vice versa.

4. The combination as in claim 1 and wherein is a single controller orlever operable for shifting the commutator from irst to secondpositionfor submergence and ycoordinately opening the oxygen shut-off valve, andvice versa, and said exhaust branch passage having a shut-off valve,with a connection from said single controller operating to close thesame when opening the oxygen valve.

5. The combination as in claim 1 and wherein the closable air inlet hasa valve with self-acting means openable to close it when submerging.

6. The combination as in claim l and wherein the closable air inlet hasa valve with self-acting means openable to close it when submerging, andthe gas outlet has a similar valve with self-acting closing means.

7. The combination as in claim l and wherein the closable air inlet hasa valve with self-acting means openable to close it when submerging,said means comprising a pressure responsive device or manometriccapsule, with a passage communieating outside pressure thereto andlocated above the emerged waterline, thereby to be operated bysubmergence, and a connection or link from the device to the valve'toclose the valve.

8. I'he combination as in claim 1 and wherein the commutator comprises ahousing or duct containing two valve seats, a movable valve stemcarrying two valve disks, one for each seat, the

shift lever connected to throw the stem and disks to their extremepositions thereby to close one and open the other valve, anda yieldablepositioning device to hold the pmts in one or the other of their extremepositions.

9. The combination as in claim 1 and where the commutator comprises ahousing containing a double valve, means to throw the double valvereversely to its extreme positions; the fuel supply comprising a tank, apipe leading from the top of the fuel tank-toward the commutator, a.chamber containing metal chips to which said pipe leads, and a `downtakepassage from the chamber to the commutator.

10. In a submarine boat containing an internal combustion engine withsupply and feed of liquid fuel thereto, a compressed oxygen supply witha regulable pressure reducer, and an engine coolingA system with forcedwater circulation; the combination of valve means delivering selectivelyeither exterior air or gas-oxygen mixture to the engine and with meansfor reversing the delivery, a gas-oxygen mixer having a passage leadingtherefrom to supply s uch mixture to the engine when running submerged,an oxygen passage leading from said pressure reducer to the mixer, andan engine exhaust gas passage having a cooling section and amufflingsection and leading thenc'e to the mixer; said cooling section adaptedby condensation to dehydrate the hot gas and deposit the condensate, andsaid muiiiing section conducting the gas through throttling andexpansion operations, thereby to extinguish pressure fluctuations andfurnish the dry gas with steady flow to the mixer. 4

11. The combination as in claim 10 and wherein`is a collector into whichthe gas condensate drains, a passage leading from the collector to theenginecooling system and pumping means. to force the ow of condensate insaid passage.

12. Ina submarine boat containing an internal combustion engine withsupply and feed of liquid fuel thereto, a compressed oxygen supply witha regulable pressure reducer, and an engine cooling system; thecombination of valve means delivering selectively either exterior air orgas-oxygen mixture to the engine, a gas-oxygen mixer having a passageleading therefrom to supply such mixture to the engine when runningsubmerged, an oxygen passage leading from said pressure reducer to themixer, an engine exhaust gas passage having a cooling section and amuffiing section and leading thence to the mixer, said cooling sectionadapted by condensation to dehydrate the hot gas and cause deposit ofcondensate and said muiiling section adaptedito extinguish pressureuctuations of the gas and supply it with steady ow to the mixer; a drainpassage' adapted to conduct such condensate and also some gas from thegas passage, and means operable to receive-the condensateand some gasthrough said drain passage and conduct the same to aplace of disposal,whereby the gas cycle may be relieved of excess of gas and pressure.

13. 'I'he combination as in claim 12 and Wherein the last-named means isa pump means arranged to suck all condensate and a variable amount ofgas from the gas passage and force the same through' means adapted toilnal disposal as by discharging exteriorly.

14. The combination as in' claim 12 and wherein the last-named means isa pump means arranged to suck all condensate and a. variable amount ofgas from the gas passage and force the same through means adapted to naldisposal as by discharging exteriorly; and self-ac ing means forregulating said pump means in a manner to relieve gas at a variable rateto deliver beyond the muilling section a substantially steady pressureof gas, said self-acting means comprising a pressure-responsive deviceor capsule in communication with the gas passage at a point between themuiing action and the mixer and connected to vary the pumping action byincreasing the action with increase of pressure and vice versa. Y I

16. The combination asin claim 12 and wherein the last-named means is apump means arranged to suck all condensate 'and a variable amount of gasfrom the gas passage and force the same through means adapted to naldisposal -as by discharging exteriorly; together withx'a the gaspressure after muiliing to increase the.. opening of said valve withincreased gas pressure and vice versa thereby to relieve excess gas andmaintain substantially steady pressure of gas now to themixer.

1'7.v In a submarine boat containing an internal combustion engine withsupply and feed oi liquid fuel thereto, a compressed oxygen supply witha regulable pressure reducer, and an engine cooling. system; thecombination of a gasoxygen mixer having a passage leading therefrom tosupply such mixture to the engine when running submerged, an oxygenpassage leading from said pressure reducer to the mixer, an engineexhaust gas passage having a cooling section and a muiiling section andleading to the mixer, said cooling section adapted for condensation todehydrate the hot gas and cause deposit of condensateya drain passageadapted to conduct such condensate and also some gas from the gaspassage, a pressure tank, and a pump operable to suck the condensateiand gas through said drain passage and force the same into said pressure18. The combination as in claim 1'? and wherein is a self-openingdischarge or safety valve delivering from said pressure tank to theexterior below water when the tank pressure reaches a predeterminedpressure.

19. In a submarine boat containing an internal combustion engine withsupply and feed of liquid fuel thereto, a compressed oxygen supply witha regulable pressure reducer, and an engine cooling system; thecombination of a gas-oxygen mixer having a passage leading therefrom tosupply such mixture to the engine when running submerged, an engineexhaust gas passage hav- '.ing a cooling section and a muiiling sectionand ,cult. l,openable to make up water losses, acond n'satedrainpassageleading downward `from Athe gasfpa'ssage ,beyond its cooling section,a.,

Y nieuwe pump to which said drain passage leads and adapted to pump thecondensate and some gas from the gas passage to said pressure tank,thereby to make the condensate available for engine cooling and tomaintain pressure in said tank.

20. The combination of claim 19 and wherein is means to regulate thepump operation to maintain steady pressure of gas flowing to the mixer,and valve-means to relieve the pressure tank of excess liquid and gas bydischarge, as exteriorly.

21.. In a submarine boat containing an internal combustion engine withsupply and feed of liquid iuel thereto, a compressed oxygen supply witha regulable pressure reducer, and an engine cooling system; theycombination of a gasoxygen mixer having a passage leading therefrom tosupply such mixture to the engine when running submerged, an engineexhaust gas pas sage having a cooling section and a muiiiing section'and leading thence to the mixer, and an oxygen passage leading fromsaid pressure reducer to the mixer with a shut-olf valve; said enginecooling system comprising a closed circuit for fresh water circulationwith a pump forcing such circulation, a closed water reserve tank, witha valved connection to the water circuit. openable to make up waterlosses in said circuit, and means for forcing into said tank water ofcondensation from the gas passage and creating pressure in the tank. v

- 22. The combination as in claim 17 and wherein is a self-openingsafety valve set for high pressure, with a manual means to open it atwill to relieve the pressure in the pressure tank and dischargeexteriorly, also a water-discharging oatvalve opened when the water inthe tank rises above a predetermined depth above the tank bottom.

23. The combination as in claim 17 and Wherein is a self-opening safetyvalve set for high pressure, with a manual means to open it at will torelieve the pressure in the pressure tank and discharge exteriorly, alsoa water-discharging floatvalve opened when the water in the tank risesabove a predetermined depthabove the tank bottom; the safety valvereceiving water and gas from artank outlet somewhat above the tankbottom, and the oat lvalve being set to discharge water rising abovesaid outlet.

24. In a submarine boat containing an internal combustion engine withsupply and feed of liquid fuel thereto, and a compressed oxygen supply;the combination of a gas-oxygen mixer having a passage leading therefromto supply such mixture to the engine when running submerged, an engineexhaust gas passage having a gas conditioning section and leading to themixer, a regulable pressure reducer for the oxygen supply, an oxygenpassage leading from said pressure reducer to the mixer with a shut-oi!valve, and means for warming the reducer comprising a relatively smallbranch pipe diverting hot gas from the gas passage, flowing it inwarming relation to the reducer and thence flowing it back to the gaspassage. p

25. In a submarine boat containing an internal combustion engine withsupply and feed of liquid fuel thereto; the combination of a gas oxygenmixer having a passageleading therefrom to supply such mixture to theengine when running submerged, anengine exhaustfgas. passage having agas conditioning section and leading tothe mixer,

a compressed oxygen supply, a regulable pressure reducer for the oxygensupply, and -an oxygen passage leading from said pressure reducer to themixer with a shut-off valve; said oxygen supply comprising a primarypressure flask communieating directly with the reducer, a series ofsupplemental flasks having a common manifold interconnecting them, afirst pipe between said manifold and the primary ask and containing acock whereby on depletion of pressure the cock may be closed to isolatethe primary flask, a second pipe between said manifold and the primaryflask, with an oxygen compressor therein operable when said cock isclosed to force oxygen from the supplemental flasks to the primary askthereby to deliver boosted pressure to the reducer.

26. In a submarine boat containing an internal combustion engine with acarbureter fed from a liquid fuel supply, a throttle lever, a compressedoxygen supply with a regulable pressure reducer, and an engine coolingsystem with forced water circulation; mixer having a passage leadingtherefrom to supply such mixture to the carbureter when runningsubmerged, an engine exhaust gas passage having a gas-conditioningsection and leading to the mixer, an oxygen passage leading from saidpressure reducer to the mixer and having a regulating valve, and anoperative connection between the carbureter throttle lever and saidregulating valve to vary the oxygen pressure or flow to the mixer inaccordance with the varying operation of the engine.

27. In a submarine boat containing an internal combustion engine withcarbureter and supply and feed of liquid fuel thereto, and a compressedoxygen supply; the combination of a gasoxygen mixer ,having a passageleading therefrom to supply such mixture to the carbureter in place ofair when running submerged, an engineexhaust gas passage having a gasconditioning sectionV and leading to the mixer, a regulable pressurereducer for the oxygen supply, an oxygen passage leading from saidpressure reducer to the mixer with a shut-off valve, and an operatingconnection between the carbureter and reducersuch that when thecarbureter is throttled for reduced engine operation the reducer isfurther closed.

the combination of a gas-oxygeny 28. In a submarine boat containing aninternal combustion engine with supply and feed of liquid fuel thereto,and a compressed oxygen supply; the combination of a gas-oxygen mixerhaving a passage leading therefrom to supply such mixture to the enginewhen running submerged, an engine exhaust gas passage having a gasconditioning section and leading to the mixer, and a regulable pressurereducer for the oxygen supply, with a valved passage leading from saidreducer to the mixer; said mixer comprising a section of duct throughwhich the gas stream iiows and with means to introduce oxygen into thestream, a longitudinal interior shaft having a bearing supported fromthe duct wall, a first propeller or screw vane on said shaft rotated bythe force of the entering gas stream, a second propeller on the shaftbeyond the oxygenadmission and driven by therotation of the firstpropeller,

to create turbulence in the mixture, and a baille or rib beyond thesecond propeller.

29. In a submarine boat containing an internal combustion engine withsupply and feed of liquid fuelv thereto, and a compressed oxygensupply;7

Avane on said shaft rotated by the force of the.

gas flowing into the duct, thereby to rotate the shaft, a secondpropeller on the shaft beyond the bearing web and oxygen apertures andof smaller effective area than the first propeller, and an annularbaille beyond the second propeller; the second propeller creatingturbulence between it and said barile for thorough mixing of gas andoxygen before passing to the engine.

GIANNI CAPRONI.

CERTIFICATE OF CORRECTION.

Patent No. 2,187,07ii.

January 16, 19h0.

GIANNI CAPRONI It is hereby certified that error appears in the printedspecification of the above numbered patent requiring correctionasfollows: Page 7, 'second column, line 35, claim 29, after the word "and"insert with peripheral apertures for circumferential; line 56, sameclaim, for "waoll" readwall; and that the said Letters Patent shouldberead with this correction therein that the same may conf'om to therecord of' the case inthe Patent Of`fic'o.

Signed and sealed this 12th day of March, A. .D. 19li0.

. .(Seal) Henry van Arsdale,

Acting Coimnissioner ofl Patents.

' Patent No. 2,187,071

CERTIFICATE 0F CORRECTION.

January 16, 1911,'0.

A GIANNI CAPRONI.

It is hereby certified that error appears in the printed specificationofthe above numbered. patent requiring correctionas follows: Page 7,'second column, vline 55, c1a1m29, after the word "and" insert withperipkvuarmll apertures for circgmgferential'; line 56,- same claim, forwaoll read wall;

and that the said Letters Petent shouldbe read with this correctionthere A i'n ythat 'the same may confonn to the record of the case inthePatent Office..

Signed and sealed this 12thday-of March, 'A. ,D. 1914.0.

Henry Van Arpdale .(Seal) Acting Comissioner of, Patents.

